<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>websocket通讯</title>
</head>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
<script>
    var socket;
    function openSocket() {
        if(typeof(WebSocket) == "undefined") {
            console.log("您的浏览器不支持WebSocket");
        }else{
            console.log("您的浏览器支持WebSocket");

            var socketUrl="ws://localhost:8080/testdemo/ws/"+$("#userId").val();
            // socketUrl=socketUrl.replace("https","ws").replace("http","ws");
            console.log(socketUrl)

            socket = new WebSocket(socketUrl);
            //打开事件
            socket.onopen = function() {
                console.log("websocket已打开");
                //socket.send("这是来自客户端的消息" + location.href + new Date());
            };
            //获得消息事件
            socket.onmessage = function(msg) {
                console.log(msg.data);
                //发现消息进入    开始处理前端触发逻辑
            };
            //关闭事件
            socket.onclose = function() {
                console.log("websocket已关闭");
            };
            //发生了错误事件
            socket.onerror = function() {
                console.log("websocket发生了错误");
            }
        }
    }
    function sendMessage() {
        if(typeof(WebSocket) == "undefined") {
            console.log("您的浏览器不支持WebSocket");
        }else {
            console.log("您的浏览器支持WebSocket");
            console.log('[{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}]');
            socket.send('[{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}]');
        }
    }
</script>
<body>
<p>【userId】：<input id="userId" name="userId" type="text" value="${userId}">
<p>【toUserId】：<input id="toUserId" name="toUserId" type="text">
<p> [发送内容]：<input id="contentText" name="contentText" type="text" maxlength="50">
    <input type="button" onclick="openSocket()" value="开启socket" style="background: cyan;background-color: green;width: auto;height: auto;"/>
    <input type="button" onclick="sendMessage()" value="发送消息" style="background: cyan;background-color: lightgrey;width: auto;height: auto;" />
</body>

</html>